Topology Optimization In Automotive Bumper Beam Design.

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TOPOLOGY OPTIMIZATION IN AUTOMOTIVE BUMPER BEAM DESIGN

AZIZUL HILMI BIN HAJI AHMAD

This report is to be present as criteria to fulfill a part of bestowal stipulation for Bachelor’s Degree in Mechanical Engineering (Design & Innovation)

Faculty of Mechanical Engineering Universiti Teknikal Malaysia Melaka

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‘I / we* admit that have read this

work and in opinion of me / we* this work was

adequate from the aspect scope and quality to the significance to awarded Bachelor Degree of Mechanical Engineering (Design & Innovation)’

Signature :………

Supervisor Name :………

Date :………...

Supervisor Name :………

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“I admit this report is produce by my own except summary and passage which each of it I already notify the source”

Writer name :………

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Alhamdulillah, with the name of Allah, with His blessing and generosity, I have finally completed this project successfully. I would like to take this opportunity to convey my thankfulness and appreciation to my projects supervisor, Mr. Mohd. Ruzi Bin Haji Harun for his excellent supervision, guidance, endeavor in making this project a triumph; as I gained a magnificent and valuable knowledge that no book would have written.

As well, I would also like to express my appreciation to the cooperation from the

management of laboratory, especially the technicians in helping my experiment in the laboratory for their generous and enthusiastic help.

My greatest appreciation goes to my beloved family especially my father and mother for their encouragement, guidance and support upon me to go through this project. Also thanks to my brothers and sisters who support me in making this project successful.

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Sistem palang bamper automotif memainkan peranan penting bukan sahaja menyerap hentakan pelanggaran tetapi juga sebagai satu gaya reka bentuk. Banyak perhatian di dalam industri automotif telah difokuskan ke atas berat, keselamatan dan juga pengurangan penggunaan bahan sejak bertahunDtahun kebelakangan ini berdasarkan reka bentuk pengoptimuman. Teknik pengoptimuman topologi digunakan dalam mengoptimumkan rekabentuk palang bamper. Untuk projek ini, palang bamper Perodua Myvi telah dipilih sebagai kes kajian. Gambaran keseluruhan prosedur pengoptimuman

topologi dan sesetengah perkara berkaitan dalam industri automotif berkaitan reka bentuk palang bamper dijelaskan dengan teliti dalam laporan ini. Reka bentuk palang

bumper telah dioptimumkan berdasarkan teknik pengoptimuman topologi dan hasilnya empat rekabentuk konsep telah dibangunkan menggunakan perisian SolidWorks. Kemudian rekabentuk yang telah dioptimumkan dianalisis berdasarkan prestasi impak palang bamper menggunakan perisian analisis COSMOSWORKS Designer. Setelah dianalisis, keputusan analisis bagi setiap reka bentuk konsep tersebut dibandingkan untuk memilih reka bentuk optimum yang terbaik berdasarkan kajian optimum yang mangandungi fungsi objektif, perubahan reka bentuk dan kekangan. Daripada kajian ini didapati reka bentuk konsep 2 adalah reka bentuk optimum yang terbaik kerana ia

memenuhi kriteriaDkriteria kajian optimum tersebut. Akhir skali, penggunaan

pengoptimuman topologi sepanjang proses pembangunan palang bamper automotif dibincangkan, termasuk mengenalpasti kebaikannya.

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Automotive bumper beam system plays a very important role not only absorbing impact energy but also in a styling stand point. A great deal of attention within the automotive industry has been focused upon light weight, sufficient safety and also less material used in recent years based on optimization design. Topology optimization technique was used to optimize bumper beam design. For this project Perodua Myvi bumper beam was selected as the case study. An overview of topology optimization procedure and some closely related subjects in automobile industry focused on bumper

beam design explained in details in this report. The bumper beam design was optimized base on topology optimization technique and the outcome is four concept design were

developed using SolidWorks software. The optimized design then analyze regarding the impact performance using COSMOSWORKS Designer analysis software. From the analysis results then the four design concept have been compared to select the best optimized design base on the optimization study which defined by objective function, design variable and constraints. It was found that design concept 2 is the best optimized design because it fulfills the optimized study criteria. Finally, the application of topology optimization during the development process of an automotive bumper beam is discussed, including identification of its major benefits.

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1.1 Project Background 1

1.2 Problem Statement 1

1.3 Objectives of Project 2

1.4 Scopes of Project 2

1.5 Project Flow Chart 3

1.6 Significant of Project 4

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1.7 Summary 4

2.1 Introduction 5

2.2 Topology Optimization 5

2.2.1 Topology Optimization Applications 7

2.3 Computer Aided Engineering (CAE) 8

2.3.1 CAE Tools 8

2.3.2 CAE Applications 9

2.3.3 CAE In Auto Industry 10

2.2.4 COSMOSWORKS Software 11

2.3.5 Advantages of CAE 13

2.4 Computer Aided Design (CAD) 14

2.4.1 Software 15

2.4.2 Applications of CAD 16

2.4.3 Software Technologies 17

2.4.4 Hardware And OS Technologies 18

2.4.5 The CAD Operator 18

2.4.6 Advantages of CAD 20

2.4.7 Disadvantages of CAD 21

2.5 Rapid Prototyping (RP) 22

2.5.1 Types of RP Machine 22

2.5.2 RP Application 23

2.5.3 Advantages of RP 23

2.5.4 Disadvantages of RP 23

2.6 Automotive Bumper Beam 25

2.7 Summary 28

3.1 Introduction 29

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3.2 Method 31

3.2.1 Mathematical Programming Method 31

3.2.2 Optimum Criteria Method 32

3.2.3 Product Development Cycles Method 33

3.3 Summary 35

4.1 Introduction 36

4.2 Literature Search 38

4.3 Develop Concept in 2D Topology

Optimization Procedure

38

4.3.1 Defining and Running The Initial Studies

40

4.3.2 Evaluating The Results of Initial Studies

40

4.3.3 Defining The Optimization Study 41

4.4 Refine 2D Concept into 3D Modeling 41

4.5 Investigate and Analyze The Impact Performance of Bumper Beam

42

4.7 Summary 43

5.1 Introduction 44

5.2 Original Design 45

5.2.1 Design Specification 46

5.2.2 Material 46

5.3 Design Concept 1 48

5.3.2 Material 49

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5.4.2 Material 51

5.5.2 Material 53

5.6.2 Material 55

5.7 Summary 56

!

6.1 Introduction 57

6.2 Analysis 57

6.2.1 Analysis Procedures 59

6.3 Results Analysis 63

6.3.1 Materials 63

6.3.2 Load & Restraints Information 64

6.3.3 Mesh 64

6.3.4 Stress, Displacement and Strain Results

68

6.4 Summary 74

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7.1 Introduction 75

7.2 Design Comparison 75

7.3 Summary 80

" # "

8.1 Conclusion 81

8.2 Recommendation 82

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" "

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1.1 Project Flow Chart 4

2.1 Topology Optimization 7

2.2 Design Configuration of Topology Optimization 7

2.3 An Example of CAE Software 11

2.4 Elements model 13

2.5 Element nodes 13

2.6 CAD Development Process 15

2.7 An Example of CAD Software 16

2.8 3D CAD Model 17

2.9 An Example of CAD Engineering Drawing 20

2.10 Automotive Bumper Beam System 26

2.11 An Example of Bumper Crash Simulation 27

3.1 Topology Optimization Process 31

4.1 Method Flow Chart 38

4.2 Topology Optimization Procedures 40

4.3 Bumper beam impact test based on Euro NCAP 43

5.1 Perodua Myvi bumper beam 45

5.2 Bumper beam 3D CAD model using SolidWorks

2007

46

5.3 Bumper beam detail design 47

5.4 Material specifications (source from SolidWorks

2007)

48

5.5 Bumper beam design concept 1 49

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5.6 Bumper beam concept 1 detail design 50

6.1 The bumper beam impact test simulation 59

6.2 Restraint is set in the COSMOSWORKS Designer 60

6.3 Force is set in the COSMOSWORKS Designer 61

6.4 Setting the mesh 61

6.5 Meshing result 62

6.6 The impact analysis is running in the

COSMOSWOKS Designer

62

6.7 Stress, displacement and strain results 63

6.8 Stress graph for the original bumper beam design 68

6.9 Displacement graph for the original bumper beam 70

6.10 Strain graph for original bumper beam 72

7.1 Mass vs. design graph 76

7.2 Min stress vs. design graph 77

7.3 Max stress vs. design graph 78

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6.1 Materials results 64

6.2 Restraint and load information 64

6.3 Original design mesh information 65

6.4 Design concept 1 mesh information 65

6.8 Stress results table 69

6.9 Displacement results table 71

6.10 Strain results table 73

7.1 Bumper beam thickness comparison 76

7.2 Bumper beam mass comparison 76

7.3 Bumper beam stress limit 77

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PSM Projek Sarjana Muda

UTeM Universiti Teknkal Malaysia Melaka

FKM Fakulti Kejuruteraan Mekanikal

CAD Computer Aided Design

CAE Computer Aided Engineering

RP Rapid Prototyping

FEA Finite Element Analysis

FEM Finite Element Method

CFD Computational Fluid Dynamics

MES Mechanical Event Simulation

SLA Stereolithography Apparatus

3DP ThreeDDimensional Printing

FDM Fused Deposition Modeling

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$ %&'()* +),-%&./0

This project will focus on how to produce innovative design of automotive bumper

beam using topology optimization procedure. The project will start from studying the topology optimization in detail that will be applied in designing automotive bumper

beam. Then generate conceptual design using Computer Aided Design (CAD) software and develop the concept in 2D topology optimization procedure and lastly, investigate and analyze the impact performance of bumper beam using COSMOSWORKS Designer software.

Since the topology optimization procedure in especially in automotive development industry is still new in UTeM, the project was chosen to expose the application of this process to all students in UTeM especially the mechanical engineering student. This project also describes the advantages and disadvantages using this procedure.

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Fuel price increase situation currently increasingly onerous vehicle consumer. Various stateDofDtheDart technologies to the car were created in order to reduce fuel

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consumption without effect the performance of the car itself. One of the aspects is reducing the weight of the car because the more weight of the car the more fuel per kilometer is used. Thus, in this case study I will focus on designing lighter car bumper beam using topology optimization procedure. The optimized bumper beam design that will improved fuel economy and performance of a car.

Topology optimization procedure in automotive industry is still new in UTeM and students here are not familiar with this process. Students also did not know the capability of this kind of method in producing the most optimize design in the beginning of product design development process with shorter lead time by using the applicable CAE software. Furthermore, the using of the Computer Aided Engineering (CAE) optimization software among UTeM’s students is quite rare.

$ 1'()*45(6 &7 %&'()*

The objectives of the project are:

a) To produce innovative design of automotive bumper beam using topology optimization method focused on Perodua Myvi bumper beam.

b) Design lighter bumper beam that will improved fuel economy and performance of a car.

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The scopes of the project are:

a) To study the topology optimization.

b) To generate conceptual design using CAD software.

c) To develop concept in 2D topology optimization procedure.

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d) To refine 2D concept into 3D modeling using solid modeling software.

e) To investigate and analyze the impact performance of bumper beam using COSMOSWORKS Designer software.

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4-.%( $ shows the project flow chart for PSM 1 and PSM 2:

4-.%( $ Project flow chart

No

Yes

Project presentation Generate conceptual design using

CAD software

Investigate and analyze the impact performance of bumper beam Develop concept in 2D topology

optimization procedure Study topology optomization

Problem statement

Literature review on automotive bumper beam design

Refine 2D concept into 3D modeling

PSM 1

PSM 2

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$ 4-/474)+/* &7 %&'()*

To see the potential of this topology optimization procedure, an automotive bumper beam was selected for this project. The development concept of the bumper beam will be done in 2D topology optimization procedure using CAD optimization software. Then, from the 3D modeling concept, investigate and analyze the impact

performance of bumper beam using COSMOSWORKS Designer software.

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Thus, hopefully this report will be reference to the UTeM’s mechanical student about the important and capability of using this topology optimization method especially in automotive development.

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In this chapter explain in details about all topics that related in this project. The

subject that will be covered are topology optimization, automotive bumper beam, computer aided design (CAD), computer aided engineering (CAE), rapid prototyping

(RP) and automotive bumper beam.

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One of the important modifications that could greatly influence the overall automotive frame or structure performance while reducing mass is optimization analyses. Successive optimization analyses would be performed to determine the optimal architecture, gauges, section sizes and shapes. Finite elementDbased structural analyses and optimization software tools would be used to design and optimize structures.

One type of the optimization analyses is topology optimization. Topology optimization generates an optimal material distribution for a set of loads and constraints within a given design space. The design space can be defined using shell elements, solid elements, or both. In the classical topology optimization setup, global loads and boundary conditions are applied to acquire the load paths (i.e., optimal design structure)

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by solving the minimum compliance problem. Manufacturing constraints can also be imposed using minimum member size and draw direction constraints [3]. 4-.%( $ shows the basic process of topology optimization.

4-.%( $ Topology optimization

Topology optimization is the latest type of optimization for the area of mechanically loaded components. With topology optimization structural parts are identified which do not contribute to the components behavior. In other words, in given design space material is distributed in such a away that under certain constrains specific objectives are met. 4-.%( $ illustrates on the design configuration of topology optimization.

4-.%( $ Design configuration of topology optimization

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$ $ &8&2&-; 8*434<+*4&/ 8824)+*4&/6

Currently, there are three main fields where topology optimization is applied:

a) The very early design phase, where the design can easily be changed. Here the topology optimization starts from a rough design proposal.

b) When potential for reducing the components stresses and weight needs to be

identified. Here the topology optimization starts from an already existing design model.

c) When parts of an already existing structure are completely redesign.

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ComputerDaided engineering (often referred to as CAE) is any use of computer software to solve engineering problems. In addition, CAE is the application of computer software in engineering to analyze the robustness and performance of components and assemblies. It encompasses simulation, validation and optimization of products and

manufacturing tools. With the improvement of graphics displays, engineering workstations, and graphics standards, CAE has come to mean the computer solution of engineering problems with the assistance of interactive computer graphics.

CAE software is used on various types of computers, such as mainframes and superminis, engineering workstations, and even personal computers. The choice of a computer system is frequently dictated by the computing power required for the CAE application or the level (and speed) of graphics interaction desired. The trend is toward more use of engineering workstations, especially a new type known as supergraphics workstations [13].

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Considering information technology that provides tools and techniques to help in design and manufacturing support, the tools used are considered CAE tools. Design engineers use a variety of CAE tools, including large, generalDpurpose commercial programs and many specialized programs written inDhouse or elsewhere in the industry. Solution of a single engineering problem frequently requires the application of several CAE tools. Communication of data between these software tools presents a challenge for most applications. Data are usually passed through proprietary neutral file formats, data interchange standards, or a system database.

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A typical CAE program is made up of a number of mathematical models encoded by algorithms written in a programming language. The natural phenomena being analyzed are represented by an engineering model. The physical configuration is described by a geometric model. The results, together with the geometry, are made visible via a user interface on the display device and a rendering model (graphics image).

In the future CAE systems will be major providers of information to help support design teams in decision making. In regards to information networks, CAE systems are individually considered a single node on a total information network and each node may interact with other nodes on the network [13].

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CAE areas covered include:

a) Stress analysis on components and assemblies using FEA (Finite Element Analysis).

b) Thermal and fluid flow analysis Computational fluid dynamics (CFD). c) Kinematics.

d) Mechanical event simulation (MES). e) Behavioral Modeling (BMX).

f) Analysis tools for process simulation for operations such as casting, molding, and die press forming.

g) Optimization of the product or process.

In general, there are three phases in any computerDaided engineering task:

a) PreDprocessing – defining the model and environmental factors to be applied to

it. (typically a finite element model, but facet, voxel and thin sheet methods are also used).